A discharge lamp of this type is disclosed for example in the U.S. Pat. No. 5,420,481. This patent specification describes a discharge lamp which has outer electrodes fitted on its discharge vessel, said outer electrodes being designed as transparent ITO layers.
The European Patent Specification EP 0 334 208 describes a discharge lamp which is arranged in a reflector and whose discharge vessel is surrounded by a cylindrical vitreous heat accumulation tube. The heat accumulation tube is provided with an ITO layer in order to reduce the color temperature of the lamp by approximately 600 kelvin.
The abovementioned discharge lamps have the disadvantage that their operation from an electronic operating unit, which usually feeds the lamp with a medium-frequency supply voltage in the range of from approximately 20 kHz to 100 kHz, can interfere with the reception of radio sets.